1. Field of the Invention
The present invention relates to a lead frame, a light emitting diode having the lead frame, and a backlight unit having the light emitting diode. More particularly, the present invention relates to a lead frame of high optical reflectivity and reliability, a light emitting diode having the lead frame, and a backlight unit having the light emitting diode.
2. Discussion of the Background
In general, a light emitting diode (LED) converts electric energy into light by using compound semiconductor. The LED has merits such as a high efficiency, a long life span, and low power consumption. Furthermore, the LED is eco-friendly. Therefore, the LED may be used in various fields.
The LED may be formed by packaging a light-emitting chip mounted on a lead frame. When electric power is applied to the light-emitting chip through the lead frame, the light-emitting chip emits light.
According to a conventional LED, a lead frame coated with silver (Ag) is used in order to enhance light reflectivity. However, the lead frame coated with silver (Ag) may be vulnerable to moisture and heat, so that when the LED is used for a long time, the lead frame is corroded and darkened to lower luminance and shorten life span. In order to solve the corrosion problem, a lead frame coated with gold (Au) instead of silver was developed, but gold (Au) has relatively low light reflectivity that may lower efficiency of an LED.